This invention relates to a film magnetic head slider and a process for preparing a material for the film magnetic head slider, and particularly to a film magnetic head slider suitable for use in a magnetic recorder where the slider contacts with and slides on a recording medium, and to a process for preparing a material for the film magnetic head slider.
In the field of magnetic disc recorders, film magnetic heads have been manufactured and contact-start-stop (CSS) systems have been used to meet the recent higher recording density and higher recording capacity requirements.
In FIG. 1, one example of the structure of a film magnetic head is shown, where a circuit member 2 containing a film transducer is provided at one end of a slider 1.
In the CSS system, the magnetic head slider flies usually at a small clearance of 0.2 to 0.5 .mu.m over the magnetic disc to increase the recording density, but contacts with and slides on the magnetic disc surface at the start and stop to rotate the magnetic disc. Furthermore, the magnetic head slider flies with a small flying height even during the flying period, and thus if the magnetic disc has flaws, tiny projections, or dusts on the surface, the magnetic disc has correspondingly a higher contact or sliding frequency. Under these circumstances, the reliability of a magnetic recorder greatly depends on the sliding characteristics of the magnetic head slider.
As a material for the magnetic head slider, not single crystals, but polycrystals and sintered materials are used on the grounds of low production cost, etc. For example, sintered Al.sub.2 O.sub.3 -TiC material is disclosed in U.S. Pat. No. 4,251,841 as such a material. Such a material has a good wear resistance and a good machinability, but its sliding characteristics fail to satisfy the desired reliability. That is, the binder which covers the magnetic disc surface is softened due to the heat of sliding friction and is liable to stick to the magnetic head to cause so called head crash. To overcome these disadvantages, it has been proposed in Japanese Patent Application Kokai (Laid-open) NOs. 56-111,166, 56-47,956, 56-107,326, and 56-169,264 to impregnate or overcoat the magnetic disc-facing side of the slider with a good lubricating material. However, the effect cannot be maintained for a long time with a thin overcoating, whereas with a thick overcoating, the clearance from the head to the magnetic disc recording surface is larger, and thus the recording density and the recording precision are adversely influenced thereby. In the case of impregnating the pores in the sintered material with a good lubricating material, the slidability can be improved, but the magnetic head may stick to the magnetic disc owing to the excretion of the lubricating material from the pores.
Japanese Patent Application Kokai (Laid-open) No. 58-121,179 discloses a magnetic head slider made from zirconia ceramics, where the applicable zirconia ceramics are selected only in view of their density, and there still are machining problems.